If I be I, as I think I be,
I’ve a little dog at home, and he’ll know me.
It is a safe ‘working hypothesis’ that when I go home in the afternoon, my wife, children, and little dog will recognise me as being ‘I myself I;’ but why or how I am I, whether I was I before I was born, or shall be so after I am dead, I really know no more than the little dog who wags his tail and yelps for joy when he recognises my personal identity as something distinct from his own, when he sees me coming up the walk.
Our conceptions, therefore, are necessarily based on our perceptions, and are what is called anthropomorphic. The term has almost come to be one of reproach, because it has so often been applied to religious conceptions of a Deity with human, though often not very humane, attributes; but, if considered rightly, it is an inevitable necessity of any attempt to define such a being or beings. We can only conceive of such as of a magnified man, indefinitely magnified no doubt, but still with a will, intelligence, and faculties corresponding to our own. The whole supernatural or miraculous theory of the universe rests on the supposition that its phenomena are, in a great many cases, brought about, not by uniform law, but by the intervention of some Power, which, by the exercise of will guided by intelligent design, alters the course of events and brings about special effects. As long as the theory is confined to knowable transformations of existing things, like those which are seen to be affected by human will, it is not necessarily inconceivable or irrational. Inferring like effects from like causes, the hypothesis was by no means unreasonable that thunder and lightning, for instance, were caused by some angry invisible power in the clouds. On the contrary, the first savage who drew the deduction was a natural philosopher who reasoned quite justly from his assumed premises. Whether the premises were true or not was a question which could only be determined centuries later by the advance of accurate knowledge.
When do we say we know a thing? Not when we know its essence and primary origin, for of these the wisest philosopher is as ignorant as the rudest savage; but when we know its place in the universe, its relation to other things, and can fit it in to that harmonious sequence of events which is summed up in what are called Laws of Nature. The highest knowledge is when we can trace it up to its earliest origin from existing matter and energy, and follow it downwards so as to be able to predict its results. The force of gravity affords a good illustration of this knowledge, both where it comes up to, and where it falls short of, perfection.
Newton’s law leaves nothing to be desired as regards its universal application and power of prediction; but we do not yet fully understand its mode of action or its relation to other forms of energy. It is probable that some day we may be able to understand how the force of gravity appears to act instantaneously at a distance, and how all the transformable forces, gravity, light, heat, electricity, and molecular or atomic forces, are but different manifestations of one common energy. But in the meantime we know this for certain, that the law of gravity is not a local or special phenomenon, but prevails universally from the fixed stars to the atoms, from the infinitely great to the infinitely small. This is a fact to which all other phenomena, which are true facts and not illusions, must conform.
In like manner, if we find in caves or river-gravels, under circumstances implying enormous antiquity, and associated with remains of extinct animals, rude implements so exactly resembling those in use among existing savages, that if the collection in the Colonial Exhibition of stone celts and arrow-heads used by the Bushmen of South Africa were placed side by side with one from the British Museum of similar objects from Kent’s Cavern or the caves of the Dordogne, no one but an expert could distinguish between them, the conclusion is inevitable that Devonshire and Southern France were inhabited at some remote period by a race of men not more advanced than the Bushmen. Any theory of man’s origin and evolution which is to hold water must take account of this fact and square with it. And so of a vast variety of facts which have been reduced to law and become certainly known during the last half-century. A great deal of ground remains unexplored or only partially explored; but sufficient has been discovered to enable us to say that what we know we know thoroughly, and that certain leading facts and principles undoubtedly prevail throughout the knowable universe, including not only that which is known, but that which is as yet partially or wholly unknown. For instance, the law of gravity, the conservation of energy, the indestructibility of matter, and the law of evolution, or development from the simple to the complex.